Treating textile material and product thereof



talented Apr. 19, 1938 UNITED STATES PATENT OFFICE TREATING TEXTILEMATERIAL AND PRODUCT THEREOF George Schneider, Montclair, N. J.,assignor to Celanese Corporation of America, a corporation of Delaware 4Claims.

This invention relates to the treatment of textile materials made of orcontaining organic derivatives of cellulose and relates more.particularly to the treatment of such materials with hot aqueous fluids.

This application is a division of my application Serial No. 616,573filed June 10, 1932, now Patent No. 2,041,868, patented May 26, 1936. I

An object of my-invention is to protect textile materials comprisingorganic derivatives of cellulose against. impairment of desirableproperties when subjected to hot aqueous fluids. A further object of myinvention is to diminish or prevent the tendency of pile of organicderivative of cellulose yarn to agglomerate when fabric having a pile oforganic derivative of cellulose yarn is subjected to hot aqueousliquids. Other objects of this invention will appear from the followingdetailed description.

Fabrics having a pile made of yarn of cellulose acetate or other organicderivative of cellulose present serious dimculties when subjected tofinishing treatments such as dyeing, scouring, degumming, etc. whichinvolve treatment with hot aqueous liquids. I have found that when suchfabrics are treated with hot aqueous liquids, the pile yarns tend toagglomerate into tufts, with the result that the appearance of thefabric is not uniform and the value of the fabric is greatly impairedthrough the lack of uniform lustre or sheen demanded of velvets or otherpile fabrics.

I have found-that if readily ionizable salts are present while such pilefabrics are treated with hot aqueous fluids the agglomeration of theorganic derivative of cellulose pile yarn into tufts is avoided, thusmaking possible the finishing of fabric made of organic derivative ofcellulose pile to form a fabric having substantially uniform sheen.

I have further found that if such neutral salts are present in a bathemployed to degum the natural silk in a mixed fabric containing bothorganic derivative of cellulose yarn and natural silk yarn; they protectthe organic derivative of cellulose yarn against the deleterious actionof the hot soap solutions employed for the degumming.

In accordance with one aspect of my invention, I treat fabricscontaining both yarns of organic derivative of cellulose and naturalsilk yarns in the gum at elevated temperatures with a degumming bathcontaining a readily ionizable salt or other compound. In accordancewith another aspect of .my invention, I treat fabric having a pile madeof yarns of organic derivative of cellulose with hot aqueous bathscontaining such salts or compounds, in order to avoid the agglomerationof the pile into tufts.

The textile material may contain or be made of any suitable organicderivative of cellulose such as organic esters of cellulose andcellulose ethers. Examples of organic esters of cellulose are celluloseacetate, cellulose formate, cellulose propionate and cellulose butyrate,while examples of cellulose ethers are ethyl cellulose, methyl cellulose and benzyl cellulose. This invention however will be describedmore specifically in connection with the treatment of textile materialsmade of or containing the acetone-soluble type of cellulose acetate.acetate of relatively high acetyl value, say 57 to 59% determined asacetic acid, is employed in making the textile material, particularlygood results are obtained due to the greater resistance of suchcellulose acetate to the agglomerating action of hot aqueous liquids.

The degumming bath employed may be the usual soap solutions used forthis purpose and usually the temperature of deming will be on the orderof to C.

Any suitable readily ionizable salt may be employed to preventagglomeration of the organic derivative of cellulose yarn. Examples ofsuch salts are the sulfates, chlorides, nitrates, chromates and acetatesof sodium, potassium, magnesium, ammonium or aluminum. The amount ofthese salts present will vary with the specific salt used, thetemperature of treatment and other considerations. Generally the saltswill be pres? ent in the aqueous liquid in a concentration of 0.5 to10%. Materials other than salts may be used for this purpose, an exampleof which is cane sugar.

Since the ionizable salts tend to reduce the alkalinity of the soapsolutions used for degumming and therefore diminish the power of thebath to degum the natural silk, I prefer to add such an amount of alkalior alkaline salt to the soap solution containing these salts as toimpart to it the degree of alkalinity of soap baths ordinarily used fordegumming natural silk and having a pH value of above 8 and preferablybelow 10, when yarns of cellulose acetate or other organic esters ofcellulose are present and it is desired to avoid substantialsaponiflcation of the same. By raising the degree of alkalinity of thedegumming bath in this manner, the time-required for degumming isreduced. Alkalies or strongly alkaline salts such as sodium hydroxide.

l6 If an acetone-soluble cellulose potassium hydroxide, sodium carbonateor potassium carbonate may be used for this purpose, but in order torender possible a more delicate control of the alkalinity, I prefer touse less strongly alkaline salts such as disodium phosphate, dipotassiumphosphate or borax.

The treatment of pile fabric such as velvets by subjecting the same tohot finishing baths, such as'are employed in dyeing, scouring,degumming, etc., that contain these salts or substances is of greatimportance not only in the case where degumming of the natural silk yarnpresent in the backing of such fabric is to occur, but is of importancein the treatments of all kinds of fabric having a pile of organicderivative of cellulose yarn, whether the backing is also made oforganic derivative of cellulose or whether itis made of silk, cotton,regenerated cellulose, wool or any other fibres. The presence of thesesalts prevents the agglomeration of the pile into tufts and consequentformation of bald" spots in such fabric.

In order further to illustrate my invention, but without being limitedthereto, the following specific examples are given.

Example I This example is given as illustrating the use of my inventionfor both degumming natural silk in a mixed natural silk and celluloseacetate fabric and also for protecting the cellulose acetate pileagainst agglomeration.

A degumming bath is made up containing:

Grams per litre Olive oil soap 50 Disodium phosphate (Na2I-IPO4.12HzO)25 Sodium sulfate (anhydrous) 25 Example II This example is also givento illustrate the use of my invention both for degumming natural silk ina mixed natural silk cellulose acetate fabric and for protecting thecellulose acetate pile against agglomeration.

A degumming bath is made up containing:

Grams per litre Olive oil soap 50 Cane sugar 50 A velvet having a pilemade of yarn of acetonesoluble cellulose acetate and a back of naturalsilk in the gum is treated with this degumming bath at a temperature ofabout C. for 1 to 2 hours. The fabric is then subjected to any desiredfinishing treatment such as washing, dyeing, steaming, etc. The silk iscompletely degummed, and the cellulose acetate pile is free ofagglomeration and the fabric presents a uniform lustre or sheen.

It is to be understood that the foregoing detailed description is givenmerely by way of iilustration and that many variations may be madetherein without departing from the spirit of my invention.

Having described my invention, what I desire to secure by Letters Patentis:

1. Process of degumming natural silk contained in a pile fabric whichcomprises subjecting a fabric having a back containing natural silk yarnand a pile'containing organic derivative of cellulose yarn to the actionof a hot degumming bath, which bath contains sugar in a concentration ofat least 0.5%.

2. Process of degumming natural silk contained in a pile fabric whichcomprises subjecting a fabric having a back containing natural silk yarnand a pile containing cellulose acetate yarn to the action of a hotdegumming bath, which bath contains sugar in a concentration of at least0.5%.

3. In the method of treating a pile fabric having a pile comprisingyarns of organic derivative of cellulose wherein the fabric is subjectedto a hot aqueous fluid, the step of inhibiting the agglomeration of theorganic derivative of cellulose pile yarn by treating the fabric with anaqueous fluid containing sugar in a concentration of at least 0.5%.

4. In the method of treating a pile fabric having a pile comprisingyarns of cellulose acetate wherein the fabric is subjected to a hotaqueous fluid, the step of inhibiting the agglomeration of the celluloseacetate pile yarn by treating the fabric with an aqueous fluidcontaining sugar in a concentration of at least 0.5%.

GEORGE SCHNEIDER.

